Process for making concrete for application by spray gun



y 9, 1963 J. L. KEMPTHORNE 3,096,968

PROCESS FOR MAKING CONCRETE FOR APPLICATION BY SPRAY GUN Filed Sept. 14, 1960 2 Sheets-Sheet 1 Eye .4?

,INVENTOR,

y 9, 1963 J. KEMPTHORNE 3,096,968

PROCESS FOR MAKING CONCRETE FOR APPLICATION BY SPRAY GUN Filed Sept. 14, 1960 2 Sheets-Sheet 2 27 A 2e 28 R IN VENTOR.

United States Patent 3,096,968 PROCESS FOR MAKING CONCRETE FOR APPLICATION BY SPRAY GUN James Lewis Kempthorne, Springfield, NJ. (7 Ramsay Road, Montclair, NJ.) Filed Sept. 14, 1960, Ser. No. 55,911 1 Claim. (Cl. 259-147) This invention relates to a method of making concrete which is applied through a tube and a spray gun at the end of the tube.

The present method comprises mixing cement with the usual aggregate of sand and graded sizes of stone, blowing the mixture through a tube by means of compressed air, blowing dry steam into the stream of the compressed air and mentioned mixture, and injecting water into said stream adjacent the delivery end of said tube. It is necessary to use dry steam, as opposed to the usual or ordinary steam, which is wet steam, as the latter clogs the spray gun head, as found in practice and acknowledge in the published trade literature. The generation and use of dry steam has long been known for certain uses, as for the operation of steam locomotives, wherein the water is removed before the steam is injected into the cylinders but such steam has not heretofore been used in the making of concrete. A simple practical test, for determining whether the steam is dry enough for the present purpose, is to hold the hand about 15-18 inches from the spray gun head as the steam issues therefrom. If the hand remains practically dry, the steam is dry for the purpose. This steam, while substantially dry, and within the meaning of the term dry steam, has a very small amount of water in it, which amount is sufiicient to wet the cement enough to prevent it from escaping as dust clouds as it emerges from the gun head, which dust has been responsible for ordinances in some cities prohibiting the use of the spray gun method for spraying concrete. Additionally, much concrete was lost by this method.

The accompanying drawings show the essential components of previously known apparatus which may be used for carrying out the process.

In the drawings:

FIGURE 1 is a perspective view of the front of the apparatus;

FIGURE 2 is a perspective view of part of the apparatus of FIGURE 1, and

FIGURE 3 is mostly a vertical section of the apparatus of FIGURE 1.

Referring to the drawings for a detailed description thereof, and more especially to FIGURE 3, the apparatus comprises an upper compartment 25 which received a "ice dry concrete mixture through a hopper 26 when a valve 27 is opened by means of a hand-operated lever 28. The lower end of compartment 25 is closed and opened by movement of a valve 30, which is operated by a handoperated lever 32, the valve 30* being opened when the dry concrete mixture is to fall from the upper compartment 25 to compartment 3-3 below. A hollow base 35 is fastened to the bottom of compartment 33 and contains a rotating cone 37. The cone is mounted on, and for rotation with, a vertical shaft 38 which may be driven in any suitable manner. Projecting radially from the lower circumference of the cone, as shown in FIGURE 2, are spaced teeth 39 between which the concrete mixture falls when it leaves lower compartment 33. As the cone turns, the material between the teeth is brought under a blow-out tube 40. The blow-out tube 40 projects into the mentioned base 35, above the teeth of the cone, and is closed at its inner end, which terminates adjacent the cone, and is open at its bottom, from which bottom a mixture of compressed air and dry steam issues and forces the material from between the teeth, the dry steam, as aforesaid, sufliciently wetting the cement to prevent dust when sprayed. Said mixture of compressed air and dry steam enters tube 40 from a pipe 42, into which the dry steam enters from tube 44 and into which compressed air enters from pipe 45. As the concrete mixture leaves the teeth under the blow-out tube 40, it slides down an incline 47 and into a tube 49 which is secured into the base 35, and the mixture is blown through tube 49' and the spray head 50' at the end thereof. A water pipe 51, having a control valve 51 therein, supplies water to the spray head. A control valve 52 is placed in the compressed air line.

What I claim is:

The method of making concrete, comprising mixing cement with the usual aggregate of sand and graded sizes of stone, blowing the mixing through a tube by means of compressed air, blowing dry steam into the stream of the compressed air and mentioned mixture, and injecting water into said stream adjacent the delivery end of said tube.

References Cited in the file of this patent UNITED STATES PATENTS 1,161,789 Orth Nov. 23, 1915 1,437,331 Alexander Nov. 28, 1922 1,556,252 Shepherd Oct. 6, 1925 1,731,953 Thomson Oct. 15, 1929 2,340,832 Darnm et a1. Feb. 1, 1944 3,012,732 Kempthorne Dec. 12, 1961 FOREIGN PATENTS 1,001,707 France June 21, 1916 

